daily.py 文件源码

def checkStockNameChanges():
        """
        Handles the renaming of stocks in the DB that have been renamed. It will switch 
        both the name and the symbol for every table in the database. 

        Uses PANDAS to capture html tables from the NASDAQ listings containing symbol changes. 

        Returns the changes in a PANDAS frame, if any. If problem scraping NASDAQ, returns error msg.
        If code error, returns a tuple of False, error.
        """
        try:

            path = 'http://www.nasdaq.com/markets/stocks/symbol-change-history.aspx?page='
            ticker_changes = pd.DataFrame()
            for i in np.arange(100): # set the number high enough to catch all pages
                page = str(i+1)
                full_path = ''.join([path, page])
                symbol_changes = pd.read_html(full_path, header=0)[3] # note: index could change in future if html is restructured
                # concat all of the changes together
                if 'No records found.' not in symbol_changes.iloc[0][0]:
                    ticker_changes = pd.concat([ticker_changes, symbol_changes], ignore_index=True)
                else: break # drop out of loop if there's nothing left to capture

            ticker_changes.rename(columns={'Old Symbol': 'Old', 'New Symbol': 'New', 'Effective Date': 'Date'}, inplace=True)

            # check returned value
            assert isinstance(ticker_changes, pd.DataFrame), "Expected stock name changes to return pandas DataFrame. Got %r instead" % type(tickers)

            return ticker_changes

        except Exception as e:
            return False, e

    # renameStocks()
    # ************** #